Aspects of the invention relate generally to devices for switching, and more particularly to multichannel relay assemblies containing multiple in line microelectromechanical system (MEMS) switch structures for use in a Radio Frequency application.
The aspirational technical specifications for the “ideal” switch in Radio Frequency (RF) applications have been held to be approximately: high isolation (off-state capacitance (Coff))=O fF; high linearity (IIP2 and IIP3→∞; medium or higher power handling (100 mW-1 kW); no insertion loss (Ron=0Ω) over a large frequency range; and, no dc power consumption.
Success at approaching this ideal RF switch has proved elusive. Electro mechanical relays, although large and expensive and a dated technology, still are a fairly successful attempt at a well performing RF switch. Other types of RF switch technologies have included p-i-n diode and GaAs FET switches. These too have shortcomings with certain RF applications.
More recently, attempts to use microelectromechanical system (MEMS) technologies, with actuators based on piezoelectric, electrostatic, thermal, or magneto-static designs, have been made. Using MEMs offers a mix of low cost fabrication along with some of the technical performance benefits of the mechanical relays. The RF MEMs switches use micromechanical movement to achieve an open or short circuit in the RF line(s).
Accordingly, there is an ongoing need for an RF application switch that addresses some, if not all, of the technical goals in the RF community for a high performing switch along with addressing other goals, such as ease of manufacturability.